In general, a robot refers to a mechanical device automatically performing a certain operation or manipulation. A robot is often used in place of a person in an industrial field or a medical field, or is used for performing a dangerous operation in a dangerous environment, in which it is difficult for a person to act. With the development of robotics technology, robots for use in the home have recently appeared in the marketplace. Representative of such home service robots is the cleaning robot.
Currently, a cleaning robot typically includes a rotary brush configured to rotate a plurality of brushes that sweep trash into a dust box and a dust collecting blade which guides dust and other debris collected by the rotary brushes to the dust box. A cleaning robot also typically includes various sensors and a navigation function that allow the robot to recognize its position within a home and recognize room boundaries such that it can thoroughly clean every nook and corner of a room and enable the robot to start and finish cleaning by itself without receiving a separate command from a user.
Efforts to improve the cleaning performance of a cleaning robot have been underway, and as a result of such efforts, more advanced cleaning robots have been developed.
The cleaning robot generally includes a rotary brush, which is configured to rotate a plurality of brushes to sweep trashes into a dust box, and a dust collecting blade, which guides dust and other debris collected by the rotary brushes to the dust box.
FIG. 1 illustrates an example of a structure of a rotary brush and a dust collecting blade of a conventional cleaning robot.
FIG. 1 is a schematic cross-sectional view illustrating the structure of a rotary brush RBU and a dust collecting blade BL of a conventional cleaning robot. As illustrated in FIG. 1, the dust collecting blade BL is disposed such that a lower part is angled towards a traveling direction of the cleaning robot, that is, towards the rotary brush RBU. Therefore, dust and other debris collected by the rotary brush RBU are easily collected in a dust box (not shown) provided above the dust collecting blade BL.
However, when the dust collecting blade BL is diagonally disposed as illustrated in FIG. 1, if the ground surface GRD is bumpy or there is a gap in the ground surface GRD, the bottom edge of the dust collecting blade BL can become repeatedly stuck as the cleaning robot moves over bumps or gaps on the ground surface GRD, thereby causing the cleaning robot to wobble. Such wobbling may cause unwanted noise and/or cause the cleaning robot to malfunction. Further, the lifespan of the cleaning robot may be shortened due to such frequent wobbling.
In order to avoid the above-mentioned problem, the dust collecting blade BL may be arranged such that there is a predetermined gap (for example, a 1 mm gap) between the bottom edge of the dust collecting blade BL and the ground surface GRD. However, when there is a gap between the bottom edge of the dust collecting blade BL and the ground surface GRD, dust and other debris collected by the rotary brush RBU may escape through the gap, thereby reducing the cleaning robot's effectiveness. Similarly, even when there is intentionally no gap between the bottom edge of the dust collecting blade BL and the ground surface GRD, over time, the bottom edge of the dust collecting blade BL may become worn by rubbing against the ground surface GRD, thereby creating a gap between the bottom edge of the dust collecting blade BL and the ground surface GRD, thereby reducing the cleaning robot's effectiveness.
FIG. 2 illustrates another example of a dust collecting blade of a conventional cleaning robot and FIGS. 3A and 3B illustrate an operation of the dust collecting blade of FIG. 2.
FIG. 2 illustrates a cleaning robot disclosed in Korean Registered Patent No. 10-1083395 (published on Nov. 14, 2011). As shown in FIG. 2, a dust collecting blade BL, comprising an elastic material, is provided at a rear side of a rotary brush RBU with respect to the traveling direction of the cleaning robot. Similar to the dust collecting blade BL of FIG. 1, the dust collecting blade BL of FIG. 2 is arranged such that its bottom edge is angled towards the direction of travel of the cleaning robot. However, the dust collecting blade BL of FIG. 2 is different from the dust collecting blade BL of FIG. 1 in that a plurality of bars br are formed on a rear surface of the dust collecting blade BL. These bars are disposed at predetermined intervals in a horizontal direction as shown in FIG. 2. In addition, the thickness of the dust collecting blade BL and the sizes of the plurality of bars br formed on the rear surface of the dust collecting blade BL are gradually reduced towards the bottom edge of the dust collecting blade BL as shown in FIG. 2.
Referring to FIGS. 3A and 3B, the dust collecting blade BL of the cleaning robot of FIG. 2 is configured such that in a normal mode, its bottom edge is angled toward the direction of travel of the cleaning robot as illustrated in FIG. 3A in order to facilitate the collection of dust and other debris into the dust box. However, as illustrated in FIG. 3B, when the bottom edge of the dust collecting blade BL encounters bumps or gaps in the ground surface GRD, the bottom edge of the dust collecting blade BL may be bent in a direction opposite to the direction of travel of the cleaning robot due to the elasticity of the dust collecting blade BL poor operation the cleaning robot as discussed above.
Because the dust collecting blade BL is made of an elastic material, it will tend to restore to its original shape after being bent. The bars br formed on the rear surface of the dust collecting blade BL will also tend to restore the bent dust collecting blade BL. However, through continued bending over time, the ability of the dust collecting blade BL to revert back to its original shape may be diminished due to the overall shape and structure of the dust collecting blade BL. Further, over time, the bottom edge of the dust collecting blade BL may become worn by rubbing against the ground surface GRD, thereby creating a gap between the bottom edge of the dust collecting blade BL and the ground surface GRD, thereby reducing the cleaning robot's effectiveness.